A source driver for driving a liquid crystal display (LCD) may use an R-string DAC (resistance-string digital to analog converter). Such an R-string DAC used to represent the source driver may represent up to 8 bits. However, in higher resolution cases, with more than 10 bits, the number of routings and resistances which may be required increases as 2N (where N is the number of bits). Thus an area on a chip taken up by the R-string DAC will increase drastically. For this reason, the R-string DAC is not practical for high resolution.
FIG. 1 is a diagram illustrating a source driver 100 including a related 10 bit R-string DAC. In reference to FIG. 1, the source driver 100 includes a latch 110 for latching data, a DAC 120 generating an analog signal corresponding to the digital data stored in the latch and an output buffer 130 for outputting the analog signal to source lines (OUT1˜OUT(N)).
The number of the routings and resistances required to fabricate the 10-bit source driver using the R-string DAC may be 1024. In addition, 1024 switches are required to select a value of the R-string for each column. As a result, an area of a chip occupied by the R-string DAC will increase drastically.